Science has tried by the most varied methods to solve the problem. It seemed a triumph of research that Woehler produced urea, that chemists later on manufactured carbohydrates, that Fischer is on the high road to the production of synthetic albumen. What is gained by these discoveries? We bring about the same combinations as the living cell does. That is, no doubt, an interesting achievement, but its value as an addition to our knowledge on this point is infinitesimal. For we accomplish the production of sugar, urea and amine in a manner very different to that of the living cell, and he who copies the things turned out in a workshop has contributed nothing to our knowledge of the workman who plies his trade in the workshop. The dividing line between life and lifelessness was supposed to have been obliterated when elementary manifestations of life were proved to exist in inanimate matter; the Brownian movements in the smallest particles; the growth of crystals immersed in a solution of the same chemical composition as themselves; crystallization itself which represents a kind of very simple organization of matter, and at any rate proves the sway of a regulating and directive force; the tendency of certain elements to combine, which has been called their affinity. But this name is only a poetical metaphor which no one will take literally. The growth of crystals in their mother liquor is merely mechanical precipitation on their surface, an external addition of layers of the same material; but not growth by the incorporation of such matter, that is, through the absorption of nourishment. These and similar results of observation do not suffice absolutely to justify the assumption, seductive though it be, that life is a fundamental attribute of matter, that it is present everywhere though graduated in intensity, that therefore apparently inanimate matter differs not qualitatively, but only quantitatively from living beings, that life stretches in an unbroken line from the block of metal or rock, in which it is completely obscured, to man, the most highly developed organism we know of; and that at a certain point in its range it reveals itself in a form which permits no distinction between organic and inorganic matter.